Magnetic pilot relay



July 25, 1967 H. G. SHBERG 3,333,149

MAGNETIC PILOT RELAY Filed Oct. 30, 1964 2 Sheets-Sheet 1 INVENTOR m? V Him/Hwy 07/5505 gu h ATTORNEYS 2 Sheets-Sheet 2 Filed Oct. 30, 1964 INVENTOR b mm/wfifi/fiog BY Z ,flbw IL ca-A ATTORNEYS United States Patent 3,333,149 MAGNETIC PILOT RELAY Hemming G. Siiberg, Union, N.J., assignor to Wagner Electric Corporation, a corporation of Delaware Filed Oct. 30, 1964, Ser. No. 407,628 6 Claims. (Cl. 31577) The present invention relates to piloting systems for vehicle directional signal circuits or the like and more particularly to an improved pilot relay for use with shunt type flashers.

A shunt type flasher is one in which a ballast resistor or heater which is in series with the lamp load to be flashed is shunted when the lamps are to be lighted. Such type of flasher is substantially independent of load and therefore is particularly suitable :for use with variable loads. However, with piloting systems heretofore in use, it has not been possible to provide indication, as by a pilot lamp, of lamp failure when the magnitude of lamp load controlled by a single flasher varies widely. In modern signalling systems for automobiles, it is desirable to provide means for flashing all signal lamps simultaneously under emergency conditions. This doubles the load on the flasher and pilot indication of the type heretofore employed is not able to cope with such doubled load. Also, in modern automobile signalling systems, it is desirable to have signals of different intensities during day and night conditions, brighter signalling lamps and brighter pilot lamps being desirable in the day-time. Pilot signals heretofore in use were not adaptable to such dual intensity systems. The pilot relay of the present invention provides means for giving positive pilot indication when any unbalance in the lamp load occurs due to failure of one or more lamps.

More specifically, the invention comprises a relay having a core with two oppositely wound sets of windings thereon and normally of equal ampere turns. An armature carrying a contact is spring biased into engagement with a fixed contact for closure of the circuit of a pilot lamp. When the ampere turns of the windings on the core difier because of lamp failure, the core attracts the armature and opens the circuit of the pilot lamp thus signifying lamp failure. The two windings on the core of the relay can be connected to diflerent banks of signal lamps 0n the vehicle or alternately all signal lamps of the vehicle can be connected to one winding and the second winding may be connected to the pilot lamp. In this latter arrangement, there will of course be a great many more turns in the pilot Winding than in the lamp load winding. With either of the above described arrangements, when there is a failure of a signal lamp, the balance on the core is upset opening the circuit of the pilot lamp. The invention includes also a novel signal circuit incorporating the pilot relay.

For a better understanding of the invention and 0f specific embodiments thereof, reference may be had to the accompanying drawings of which:

FIGURE 1 is a side view of a combined flasher and pilot relay with the cover removed representing one embodiment of the invention;

FIGURE 2 is a plan View of the structure of FIG- URE 1;

3,333,149 Patented July 25, 1967 FIGURE 3 is a circuit diagram of an automobile signalling system employing the device of FIGURES 1 and 2 arranged also for dual intensity control of the signal lamps and for emergency flashing of signal lamps and pilot lamps simultaneously; and

FIGURE 4 is a diagram representing alternate circuit connections of the windings on the relay coil and suitable for use in the circuit of FIGURE 3 with minor modifications of that circuit.

Referring now to FIGURES 1 and 2, the particular shunt type flasher disclosed therein comprises a vane 2 which is generally rectangular in shape and is provided with two ribs 4 which bias the vane into curvature along the vertical axis, convex as viewed in FIGURE 1. An expansible pull ribbon 6 is attached under tension to diagonally opposite corners of the vane 2 and, when cold, bows the vane about the horizontal axis against the bias introduced by the ribs 4. Adjacent to the pull ribbon 6 is a mandrel 8 about which is Wound a heater 10. One end of the heater is connected electrically to the mandrel and the other end is connected to a finger 12 secured to a lug 14. The vane 2 carries a contact 16 positioned for engagement, when the pull ribbon is expanded by heat, with a fixed contact 18 also mounted on the lug 14. The mandrel 8 and vane 2 are both mounted on a bracket 20. Bracket 29 extends through a base 22 of insulating material and terminates in a prong terminal X for connection to a source of power such as the car carried battery. Lug 14, which may be considered as the output terminal of the flasher, is also mounted on and fastened to the base 22.

The above described shunt type flasher is representative of flashers of this general type that can be employed in the present invention. In operation, when a load circuit is connected to the lug 14 and a source of potential is applied to terminal X, current flows from terminal X through the heater 10, from the heater to the lug 14 and thence to the load. The current to the load will be small because of the inclusion of the heater in the circuit and any lamps in the load will not be lighted because of the small current. When, however, the heat developed by the heater causes the pull ribbon 6 to expand, the vane snaps towards its biased conformation and contact 16 engages the fixed contact 18 on lug 14 to shunt the heater from the circuit. Accordingly, full voltage is supplied to the load and the lamps light. The pull ribbon then starts to cool and contract to restore the vane to contact open position.

In accordance with the invention, there is mounted on the base 22 a relay comprising a core 24 and an armature 26. The core carries a winding 28 of relatively heavy wire, one end of which is connected to lug 14 and the other end of which is fastened to a bracket 30 also mounted on the base 22 and extending therethrough to form a prong terminal L. A second winding 32 on the core 24 is of relatively fine wire and of more turns than winding 28. One end of this winding is also connected to lug 14 and the other end is connected to a fulcrum point of the armature 26. For clarity in the drawing, the windings 28 and 32 are show spaced from each other on the core. In practice, one winding would be wound over the other to insure proper superposition of their magneth: flux. The armature 26 is of spring metal and is biased into engagement with a fixed contact 34 mounted on a third 3 bracket 36 of the device. Bracket 36 extends through the base 22 and terminates in a prong terminal P. The number of turns of the two windings 28 and 32 are correlated to the load to be carried thereby. Winding 28 carries the current for the signal lamps which would ordinarily be the front and rear signal lamps for one side of the vehicle and the winding 32 carries the current required for one pilot lamp. The turns on these two windings are such that the pilot lamp current times the number of turns of winding 32' is equal to the signal lamp current times the number of turns of winding 28. When these ampere turns are equal, the armature 26 is not attracted by the core and hence whenever the contacts are closed in the flasher, current of sufiicient magnitude to energize the pilot lamp will be available at terminal P. Should one of the signal lamps fail, then the ampere turns of the two windings on the core become unequal and the armature 26' will be attracted to open the circuit of the pilot lamp thus indicating lamp failure. 7

The above described pilot relay, when associated with a shunt type flasher such as that described, will operate in the same manner when the lamp load is doubled at the same time that the pilot load is doubled as again the two windings will have equal ampere turns. Should doubling of pilot and lamp load occurs when the signalling system is provided with means for emergency operation, that is, for flashing of all lamps simultaneously. Also, in the dual intensity system, if the lamp loads and pilot lamps for day and night operation are varied proportionately, the relay will operate as described and will indicate lamp v failure when any one or more of the signal-ling lamps fail.

In FIGURE 3 a complete automobile signalling system utilizing the pilot relay and flasher of FIGURE 1 is diagrammatically illustrated except that the flasher is shown more or less symbolically as representing any shunt type flasher. The heater 16 of the flasher is represented by a resistor connected between the input terminal X and the output terminal 14, corresponding to lug 14 of FIGURES l and 2. The vane, .pull ribbon and fixed-contact of the flasher are identified by the reference numerals employed in FIGURES 1 and 2.

In the circuit of FIGURE 3 the car carried battery, which may be nominally 12 volts, is shown at 38 with its negative terminal grounded and its positive terminal connected to terminal X of the flasher and connected also by a lead 40 to the foot-operated brake switch 42. Terminal L of the relay is connected by a lead 44 to a segment-46 of a Bell switch of modified construction and generally indicated at 48. Terminal P of the relay is connected by a lead 50 to a segment 52 of the switch 48. The left front signal lamp is indicated at 54L and the right front signal lamp at 54R. The left tail light and signal lamp is indicated at 56L and the right rear tail light and signal lamp at 56R. Each front and rear lamp has two filaments, those of the front lamps being both grounded whereas only one filament of the two rear lamps is grounded. The ungrounded filaments of the rear lamps are connected together and to a terminal of a switch 58 which, when closed, provides a ground connection for the second filament of each of the rear lamps. This switch 58 is open for night-time use and closed for day-time use to provide dual intensity. A left pilot lamp with two filaments is shown at 60 with one filament grounded and the other filament connected to the switch 58 for grounding when the switch is closed. The right pilot lamp with two filaments is shown at 62 with one filament grounded and the other connected to the switch 58 for grounding when the switch is closed.

The parts of the Bell switch 48 will now be identified and their interconnection for neutral left and right turns explained. There is an upper inverted U-shaped segment 64 which has two spaced arms between which are small segments 65 and 66. Segment 65 is connected to pilot lamp 60 and segment 66 is connected to pilot lamp 62.

Aligned with one arm of segment 64 is a segment 67 and aligned with segment 67 is an elongated segment 68 which is positioned over one arm of a U-shaped segment 70. Above the second arm of segment 70 is a second elongated segment 72 and above the inner ends of segments 68 and '72 is the segment 46 previously described as being connected to terminal L of the relay. Segment 67 is connected to a tail lamp 74. A segment 76 positioned beneath the other arm of segment 64 is similarly connected to a tail lamp 78. Between segment 52 and segment 46 are two small segments 80 and 82. Segment 80 is connected to one filament of the left front lamp 54L and segment 82 is connected to one filament of the right front lamp 54R. Both filaments of the left rear light 56L are connected to segment 68. Similarly, both filaments of the rightrear lamp 56?. are connected to segment 72.

In the neutral position of the Bell switch 48, segments 64 and 67 are connected together by a shorting bar as are segments '68 and 70. Also segment 64 and segment 76 are connected by a shorting bar as are segments 70 and 72. To avoid confusion in the drawing, these shorting bars are not illustrated but the connections effected thereby will be clear from the following table:

In the position for a left turn, voltage from terminal P of the relay is impressed upon the left pilot lamp '60 through segments 52 and 65. Voltage from terminal L of the relay is impressed on one filament of the left front lamp 54L through segments 46 and 80 and upon one filament of the left rear light 56L through segments 46 and 68. Similarly, fora right turn, terminal P is connected to the right pilot lamp 62 and terminal L is connected to one filament of the right front lamp 54R and to one'filament of the right rear lamp 56R. If switch 58- is closed for day-time operation, energization of both filaments of the pilot lamps is efiected when the Bell switch is in position for a turn as the ground for the second filament of the pilot lamp is provided at'switch 58. Similarly, both filaments of the rear lamps are energized because ground is provided for the second filament at switch 58. In the neutral position of the Bell switch, if the brake pedal closes switch 42, the battery is connected through lead 40 and segments 70, 68 and 72'to both tail lamps. If during braking switch 58 is closed for day-time operation, both filaments of both tail lights will be energized. H

For night-time operation, there is provided a lead 84 from the battery to a bridging bar 86 which when moved into contact with two terminals 88 and 90 connects segment 64 of the Bell switch to the battery and also connects one filament of each front lamp to the battery for v steady lighting. In the neutral position, segment 64 is flasher and relay and therefore has no affect upon the flasher operation.

Summarizing the description of the operation so far described, during day-time conditions, that is with switch 58 closed, when a turn signal is to be indicated, two filaments of the tail lamps are flashed and two filaments of the pilot lamp are flashed whereas but one filament of the front signalling lamp is flashed. During night operation, one filament only of the tail lamp and pilot lamp are flashed and one filament of the front signalling lamp is flashed. By proper design of the lamp filaments, the increase in the ampere turns of winding 32 of the relay coil in changing to day operation can be made equal to the increase in ampere turns in winding 28 in changing to day-time operation. Consequently, the armature 26 will not be attracted and will maintain contact with the fixed contact 34 so long as there is no failure in any signal lamp. When a lamp fails, there will be an unbalance in the ampere turns on the core and consequently the armature 26 will be attracted to maintain open the circuit of the pilot lamp.

The circuit of FIGURE 3 is also arranged for emergency operation. For this purpose, a multiple switch 92 is provided with three arms 94, 96 and 98 ganged together for conjoint operation. Movement of the switch 92 into position for emergency operation connects the P terminal of the relay to the right .pilot lamp 62 by means of arm 98, connects the L terminal of the relay to one filament of the front right lamp 54R by arm 96 and connects the L terminal of the relay to the right rear lamp 56R by means of arm 94. Thus, if the Bell switch 48 is moved into the position for a left turn and switch 92 is closed for emergency operation, all signal lamps both front and rear and both pilot lamps will flash simultaneously. This will double the load on each winding of the pilot relay but as the ampere turns of the two windings will remain equal, the pilots will function in the same way to detect and signify lamp failure.

Thus, the system of FIGURE 3 illustrates the use of the new pilot relay for giving positive pilot indication of lamp failure irrespective of the magnitude of the lamp load.

In FIGURE 4, an alternative arrangement of the pilot relay of the invention is illustrated. In this embodiment of the invention, one winding 100 of the relay is connected between the flasher output terminal and a terminal 102, the second winding 104 of the relay is connected between the flasher output terminal and a terminal 106 and the P terminal of the relay is connected through the armature when in retracted position to the flasher output terminal. Windings 100 and 104 are connected through terminals 102 and 106 respectively to equal lamp loads that are to be flashed simultaneously. For example, winding 100 could be connected to lamps on the rear of a vehicle and winding 104 connected to lamps at the front of the vehicle.

Referring to FIGURE 3, if the front and rear lights were designed to carry equal current when flashed, then winding 100 could be connected to the Bell switch to flash either the front left signal light or the front right signal lamp depending upon the position of the Bell switch and winding 104 could be connected to the Bell switch to simultaneously flash the corresponding rear lamp. Similarly, if the lamps to be flashed are those of a trailer truck and cab, the windings of the pilot relay would be connected to the proper number of lamps to insure equality of the ampere turns on the core of the pilot relay except when a lamp failure occurred. Relatively minor modification of the Bell switch would be required for use of the embodiment of FIGURE 4 in the circuit of FIGURE 3. It would only be necessary to replace segment 46 of the Bell switch with two segments, connecting one such segment to terminal 102 of the relay of FIGURE 4 and the other such segment to terminal 106 of the relay of FIGURE 4. The Bell switch would then be provided with means for connecting segment 80 for left turn and segment 82. for right turn with one of the replacement parts of segment 46 and with a separate shorting bar for connecting the other replacement part of segment 46 with segment 68 for left turn operation and with segment 72 for right turn operation.

From the foregoing description, it will be apparent that the new pilot relay when associated with a shunt type flasher provides a versatile arrangement for providing positive pilot indication under conditions of widely varying load. Although the invention has been described with specific reference to emergency and dual intensity operation of a vehicle directional signal system, obviously the invention is not limited to the specific system described. Many other applications of the invention will be apparent to those skilled in the art. The invention is to be limited only by the scope of the appended claims.

The following is claimed:

1. In a directional signal system for vehicles having a source of energy and a shunt type flasher with a terminal for connection to the source and an output terminal, a resistor connected between said terminals, and means for intermittently shunting said resistor, the combination comprising a pilot relay having a core and an armature associated therewith biased to retracted position, two oppositely wound windings on said core each connected at one end to the flasher output terminal, two lamp loads either one of which may be selectively flashed, switch means for selectively connecting either of said lamp loads to the other end of a first one of said windings, a pair of pilot lamps connected to said switch means, one of said pilot lamps being connected through said switch means and said armature when in retracted position to the other end of the second of said windings when one lamp load is connected to said one end of said first winding and the other of said pilot lamps being connected through said switch means and armature when in retracted position to the other end of the second of said windings when the other of said lamp loads is connected to the other end of said first winding, the number of turns in said windings being such than when all lamps to be flashed are functioning, the ampere turns of said two windings are equal, each of said lamp loads having a ground connection.

2. The combination according to claim 1 including means for optionally connecting both lamp loads simultaneously to the other end of said first winding and for simultaneously connecting both pilot lamps through the armature when in retracted position to the other end of said second winding.

3. The combination according to claim 1 including means for optionally increasing each lamp load and for simultaneously increasing the load of each pilot lamp proportionately to the increase in each lamp load.

4. In a directional signal system for vehicles having a source of energy and a shunt type flasher with a terminal for connection to the source and an output terminal, a resistor connected between said terminals and means for intermittently shunting said resistor, the combination comprising a pilot relay having a core and an armature associated therewith biased to retracted position, two oppositely wound windings on said core each connected at one end to the flasher output terminal, multiple switch means, a first lamp load connectable through said switch means in one position to the other end of a first one of said windings, a second lamp load connectable through said switch means in said one position to the other end of the second of said windings, a third lamp load connectable through said switch means in a second position to the other end of said first winding and a fourth lamp load connectable through said switch means in said second position to the other end of the second winding, a pair of pilot lamps, one of said lamps connectable through said switch means in said one position and through the armature in retracted position to the flasher output terminal and the other of said pilot lamps connectable through said switch means in said second position and through the armature in retracted position to the flasher output terminal, the number of turns in said windings being such that when the switch means is in either position and all lamps are functioning, the ampere turns of said windings are equal, each of said lamp loads having a ground connection.

5. The combination according to claim 4 including means for optionally connecting the first and third lamp loads simultaneously to the other end of said first winding and for simultaneously connecting the second and fourth lamp loads to the other end of said second winding and for simultaneously connecting both pilot lamps through the armature when in retracted position to said flasher output terminal.

6. The combination according to claim 4 including means for optionally and proportionately increasing each lamp load.

References Cited UNITED STATES PATENTS 10 JOHN'W. HUCKERT, Primary Examiner.

D. O. KRAFT, R. SANDLER, Assistant Examiners. 

1. IN A DIRECTIONAL SIGNAL SYSTEM FOR VEHICLES HAVING A SOURCE OF ENERGY AND A SHUNT TYPE FLASHER WITH A TERMINAL FOR CONNECTION TO THE SOURCE AND AN OUTPUT TERMINAL, A RESISTOR CONNECTED BETWEEN SAID TERMINALS, AND MEANS FOR INTERMITTENTLY SHUNTING SAID RESISTOR, THE COMBINATION COMPRISING A PILOT RELAY HAVING A CORE AND AN ARMATURE ASSOCIATED THEREWITH BIASED TO RETRACTED POSITION, TWO OPPOSITELY WOUND WINDINGS ON SAID CORE EACH CONNECTED AT ONE END TO THE FLASHER OUTPUT TERMINAL, TWO LAMP LOADS EITHER ONE OF WHICH MAY BE SELECTIVELY FLASHED, SWITCH MEANS FOR SELECTIVELY CONNECTING EITHER OF SAID LAMP LOADS TO THE OTHER END OF A FIRST ONE OF SAID WINDINGS, A PAIR OF PILOT LAMPS CONNECTED TO SAID SWITCH MEANS, ONE OF SAID PILOT LAMPS BEING CONNECTED THROUGH SAID SWITCH MEANS AND SAID ARMATURE WHEN IN RETRACTED POSITION TO THE OTHER END OF THE SECOND OF SAID WINDINGS WHEN ONE LAMP LOAD IS CONNECTED TO SAID ONE END OF SAID FIRST WINDING AND THE OTHER OF SAID PILOT LAMPS BEING CONNECTED THROUGH SAID SWITCH MEANS AND ARMATURE WHEN IN RETRACTED POSITION TO THE OTHER END OF THE SECOND OF SAID WINDINGS WHEN THE OTHER OF SAID LAMP LOADS IS CONNECTED TO THE OTHER END OF SAID FIRST WINDING, THE NUMBER OF TURNS IN SAID WINDINGS BEING SUCH THAN WHEN ALL LAMPS TO BE FLASHED ARE FUNCTIONING, THE AMPERE TURNS OF SAID TWO WINDINGS ARE EQUAL, EACH OF SAID LAMP LOADS HAVING A GROUND CONNECTION. 